Document libbabeltrace2's C API
[babeltrace.git] / src / lib / trace-ir / attributes.c
1 /*
2 * Copyright (c) 2015 EfficiOS Inc. and Linux Foundation
3 * Copyright (c) 2015 Philippe Proulx <pproulx@efficios.com>
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a copy
6 * of this software and associated documentation files (the "Software"), to deal
7 * in the Software without restriction, including without limitation the rights
8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 * copies of the Software, and to permit persons to whom the Software is
10 * furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 */
23
24 #define BT_LOG_TAG "LIB/ATTRS"
25 #include "lib/logging.h"
26
27 #include "common/macros.h"
28 #include <babeltrace2/value.h>
29 #include "lib/assert-pre.h"
30 #include "lib/object.h"
31 #include <babeltrace2/value.h>
32 #include "lib/value.h"
33 #include "attributes.h"
34 #include <inttypes.h>
35 #include "compat/string.h"
36 #include "common/assert.h"
37
38 #define BT_ATTR_NAME_INDEX 0
39 #define BT_ATTR_VALUE_INDEX 1
40
41 BT_HIDDEN
42 struct bt_value *bt_attributes_create(void)
43 {
44 struct bt_value *attr_obj;
45
46 /*
47 * Attributes: array value object of array value objects, each one
48 * containing two entries: a string value object (attributes
49 * field name), and a value object (attributes field value).
50 *
51 * Example (JSON representation):
52 *
53 * [
54 * ["hostname", "eeppdesk"],
55 * ["sysname", "Linux"],
56 * ["tracer_major", 2],
57 * ["tracer_minor", 5]
58 * ]
59 */
60 BT_LOGD_STR("Creating attributes object.");
61 attr_obj = bt_value_array_create();
62 if (!attr_obj) {
63 BT_LIB_LOGE_APPEND_CAUSE("Failed to create array value.");
64 } else {
65 BT_LOGD("Created attributes object: addr=%p",
66 attr_obj);
67 }
68
69 return attr_obj;
70 }
71
72 BT_HIDDEN
73 void bt_attributes_destroy(struct bt_value *attr_obj)
74 {
75 BT_LOGD("Destroying attributes object: addr=%p", attr_obj);
76 BT_OBJECT_PUT_REF_AND_RESET(attr_obj);
77 }
78
79 BT_HIDDEN
80 uint64_t bt_attributes_get_count(const struct bt_value *attr_obj)
81 {
82 return bt_value_array_get_length(attr_obj);
83 }
84
85 BT_HIDDEN
86 const char *bt_attributes_get_field_name(const struct bt_value *attr_obj,
87 uint64_t index)
88 {
89 const struct bt_value *attr_field_obj = NULL;
90 const struct bt_value *attr_field_name_obj = NULL;
91
92 BT_ASSERT_DBG(attr_obj);
93 BT_ASSERT_DBG(index < bt_value_array_get_length(attr_obj));
94 attr_field_obj = bt_value_array_borrow_element_by_index_const(
95 attr_obj, index);
96
97 attr_field_name_obj =
98 bt_value_array_borrow_element_by_index_const(attr_field_obj,
99 BT_ATTR_NAME_INDEX);
100
101 return bt_value_string_get(attr_field_name_obj);
102 }
103
104 BT_HIDDEN
105 struct bt_value *bt_attributes_borrow_field_value(
106 struct bt_value *attr_obj, uint64_t index)
107 {
108 struct bt_value *attr_field_obj = NULL;
109
110 BT_ASSERT_DBG(attr_obj);
111 BT_ASSERT_DBG(index < bt_value_array_get_length(attr_obj));
112
113 attr_field_obj =
114 bt_value_array_borrow_element_by_index(attr_obj, index);
115
116 return bt_value_array_borrow_element_by_index( attr_field_obj,
117 BT_ATTR_VALUE_INDEX);
118 }
119
120 static
121 struct bt_value *bt_attributes_borrow_field_by_name(
122 struct bt_value *attr_obj, const char *name)
123 {
124 uint64_t i, attr_size;
125 struct bt_value *value_obj = NULL;
126 struct bt_value *attr_field_name_obj = NULL;
127
128 attr_size = bt_value_array_get_length(attr_obj);
129 for (i = 0; i < attr_size; ++i) {
130 const char *field_name;
131
132 value_obj = bt_value_array_borrow_element_by_index(
133 attr_obj, i);
134
135 attr_field_name_obj =
136 bt_value_array_borrow_element_by_index(
137 value_obj, BT_ATTR_NAME_INDEX);
138
139 field_name = bt_value_string_get(attr_field_name_obj);
140
141 if (strcmp(field_name, name) == 0) {
142 break;
143 }
144
145 value_obj = NULL;
146 }
147
148 return value_obj;
149 }
150
151 BT_HIDDEN
152 int bt_attributes_set_field_value(struct bt_value *attr_obj,
153 const char *name, struct bt_value *value_obj)
154 {
155 int ret = 0;
156 struct bt_value *attr_field_obj = NULL;
157
158 BT_ASSERT(attr_obj);
159 BT_ASSERT(name);
160 BT_ASSERT(value_obj);
161 attr_field_obj = bt_attributes_borrow_field_by_name(attr_obj, name);
162 if (attr_field_obj) {
163 ret = bt_value_array_set_element_by_index(
164 attr_field_obj, BT_ATTR_VALUE_INDEX,
165 value_obj);
166 attr_field_obj = NULL;
167 goto end;
168 }
169
170 attr_field_obj = bt_value_array_create();
171 if (!attr_field_obj) {
172 BT_LIB_LOGE_APPEND_CAUSE("Failed to create empty array value.");
173 ret = -1;
174 goto end;
175 }
176
177 ret = bt_value_array_append_string_element(attr_field_obj,
178 name);
179 ret |= bt_value_array_append_element(attr_field_obj,
180 value_obj);
181 if (ret) {
182 BT_LIB_LOGE_APPEND_CAUSE(
183 "Cannot append elements to array value: %!+v",
184 attr_field_obj);
185 goto end;
186 }
187
188 ret = bt_value_array_append_element(attr_obj,
189 attr_field_obj);
190 if (ret) {
191 BT_LIB_LOGE_APPEND_CAUSE(
192 "Cannot append element to array value: "
193 "%![array-value-]+v, %![element-value-]+v",
194 attr_obj, attr_field_obj);
195 }
196
197 end:
198 bt_object_put_ref(attr_field_obj);
199 return ret;
200 }
201
202 BT_HIDDEN
203 struct bt_value *bt_attributes_borrow_field_value_by_name(
204 struct bt_value *attr_obj, const char *name)
205 {
206 struct bt_value *value_obj = NULL;
207 struct bt_value *attr_field_obj = NULL;
208
209 BT_ASSERT_DBG(attr_obj);
210 BT_ASSERT_DBG(name);
211 attr_field_obj = bt_attributes_borrow_field_by_name(attr_obj, name);
212 if (!attr_field_obj) {
213 BT_LOGD("Cannot find attributes object's field by name: "
214 "value-addr=%p, name=\"%s\"", attr_obj, name);
215 goto end;
216 }
217
218 value_obj = bt_value_array_borrow_element_by_index(
219 attr_field_obj, BT_ATTR_VALUE_INDEX);
220
221 end:
222 return value_obj;
223 }
224
225 BT_HIDDEN
226 int bt_attributes_freeze(const struct bt_value *attr_obj)
227 {
228 uint64_t i, count;
229 int ret = 0;
230
231 BT_ASSERT(attr_obj);
232 BT_LOGD("Freezing attributes object: value-addr=%p", attr_obj);
233
234 count = bt_value_array_get_length(attr_obj);
235
236 /*
237 * We do not freeze the array value object itself here, since
238 * internal stuff could need to modify/add attributes. Each
239 * attribute is frozen one by one.
240 */
241 for (i = 0; i < count; ++i) {
242 struct bt_value *obj = NULL;
243
244 obj = bt_attributes_borrow_field_value(
245 (void *) attr_obj, i);
246 if (!obj) {
247 BT_LIB_LOGE_APPEND_CAUSE(
248 "Cannot get attributes object's field value by index: "
249 "%![value-]+v, index=%" PRIu64,
250 attr_obj, i);
251 ret = -1;
252 goto end;
253 }
254
255 bt_value_freeze(obj);
256 }
257
258 end:
259 return ret;
260 }
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